Regimes of miscible fluid thread formation in microfluidic focusing sections
Regimes of miscible fluid thread formation in microfluidic focusing sections
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DOI：
10.1063/1.4903534
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发表时间：
2014-12-01
影响因子：
4.6
通讯作者：
Notaro, Sara
中科院分区：
文献类型：
--
作者：
Cubaud, Thomas;Notaro, Sara
利用流体动力聚焦截面，对高粘度液体混相流体螺纹的形成和稳定性进行了实验研究。可混相的核心环状流对于输送粘性物质是有用的，并且可以不稳定以加强传质。我们描绘了润滑丝从低粘度到大粘度的相图，并与各种扩散系数进行了对比。根据流体性质和注入流量的不同，稳定的微流可分为包裹型、螺纹型和管型。对于低Peclet数，我们研究了当扩散效应强烈地改变基本流动结构并诱导新的流动形态时的螺纹动力学，包括超扩散和扩散不稳定区域。在中等雷诺数的情况下，研究了另一种不稳定的流动安排，即小螺纹在流体连接处附近的鞘流体惯性流场中迅速失稳。本文综述了方形微通道中粘性流体细丝形成过程中的稳定流型和不稳定流型及其转变过程。(C)2014 AIP出版有限责任公司。
We experimentally study the formation and stability of miscible fluid threads made of high-viscosity liquids using hydrodynamic focusing sections. Miscible core annular flows are useful for transporting viscous materials and can be destabilized for enhancing mass transfer. We delineate phase-diagrams of the generation of lubricated threads from low to large viscosity contrasts with various diffusion coefficients. Depending on fluid properties and flow rates of injection, stable microflows are classified into engulfment, thread, and tubing regimes. For low Peclet numbers, we examine thread dynamics when diffusive effects strongly alter basic flow structures and induce new flow configurations, including ultra-diffusive and diffusive instability regimes. Another unstable flow arrangement is investigated for moderate Reynolds numbers where small threads are rapidly destabilized in the inertial flow field of the sheath fluid near the fluid junction. This study provides an overview of stable and unstable flow regimes and their transitions during the formation of miscible viscous fluid filaments in square microchannels. (C) 2014 AIP Publishing LLC.